1. Field of the Invention
The present invention relates to fluid and tissue collection devices and more specifically to devices for collecting and processing aspirated adipose tissue for use in autologous adipose tissue implantation procedures.
2. Background Art
Liposuction, a popular type of cosmetic surgery also known as lipoplasty, liposculpture and suction assisted body contouring, is a technique for removing adipose tissue by inserting a hollow tube, or canula, through the skin and connecting it to a vacuum pump to suction out a quantity of fatty tissue. The procedure may be used to remove unwanted deposits of excess fat, to improve body appearance, and to smooth irregular or distorted body shapes, also known as body sculpting. Liposuction may be useful for contouring almost any area of the body including under the chin, neck, cheeks, upper arms, breasts, abdomen, buttocks, hips, thighs, knees, calves, and ankle areas.
A liposuction machine and special instruments are used for this type of surgery. In general, the surgical team first preps the operative site and administers either local or general anesthesia. Through a small skin incision, a suction tube with a sharp end is inserted into the fat pockets and swept through the area where fat is to be removed. The dislodged fat is vacuumed away through the suction tube and deposited into a collection or waste canister. A vacuum pump or a large syringe generates the negative pressure to aspirate the fatty tissue.
In addition to removing unwanted fat, the harvested fat may be re-introduced back into the patient. This is referred to as adipose tissue transplantation. It is preferred to use the patient's own fatty tissue (autologous adipose tissue implantation) since it is more likely to be accepted. Using the patient's own tissues also reduces or even eliminates the need for testing for allergic reactions and the filling replacement tissue may be permanent. Given the decline and drawbacks in the use of foreign substances such as synthetic materials like silicone and teflon as well as the use of foreign tissues such as bovine collagen, and the advantages of autologous adipose tissue, the interest in and demand for this autologous adipose tissue transplantation continues to increase.
Autologous adipose tissue (or fatty tissue) transplantation is performed by many surgeons for various cosmetic and reconstructive procedures, particularly those relating to the face, hands and other areas. More specifically, autologous fat transplantation involves retrieving adipose tissue using liposuction techniques from an area of abundance and then re-injecting the harvested adipose tissue into a different site of the same individual for cosmetic/reconstructive augmentation or enhancement purposes. Generally, prior to the re-introduction of the tissue into the patient, the adipose tissue must be processed or cleaned to maximize the chances of implant survival. Such processing is preferably accomplished while minimizing the exposure of the tissue to air as possible. However, the adipose cells are relatively delicate and the number of steps and length of time required to separate and process the harvested tissue prior to re-introduction into the patient contributes directly to the success of the operation and decreases the likelihood the tissue will be rejected.
The more commonly used aspiration based liposuction techniques include Tumescent Liposuction, Wet and Super-Wet Liposuction, and Power-Assisted Liposuction (PAL). Tumescent liposuction is the most common type of liposuction. It involves injecting a large amount of medicated solution into the areas before the fat is removed. Frequently, the solution may be up to three times the volume of fat to be removed. The fluid is a mixture of local anesthetic such as lidocaine, a drug that contracts the blood vessels such as epinephrine, and an intravenous (IV) salt solution. The lidocaine in the mixture helps to numb the area during and after surgery, and may be the only anesthesia needed for the procedure. The local anesthesia also contributes to the tumescence (swollen and firm) of the target fat. The epinephrine in the solution helps reduce the loss of blood, the amount of bruising, and the amount of swelling from the surgery. The IV solution helps remove the fat more easily and it is suctioned out along with the fat. This type of liposuction generally takes longer than other types. Less blood is also extracted along with the fat over the wet and super-wet techniques.
The wet and super-wet techniques are similar to tumescent liposuction. The difference is that not as much fluid is used during the surgery—the amount of fluid injected is equal to the amount of fat to be removed. This technique takes less time; however, it often requires sedation with an IV or general anesthesia. Surgical blood loss is less for the super-wet technique than the wet technique but still more than the tumescent technique.
Power-assisted liposuction uses an electric variable speed motor to generate a reciprocating motion and move the canula back and forth in a way that mimics the movement made by a surgeon. It decreases the effort required and allows easier fat extraction.
Unfortunately, the nature of liposuction procedures preclude easy tissue isolation after initial harvest, especially on a large scale, because the volume and/or viscosity of the extracted liposuction effluent also contains unwanted components such as oil, blood and anesthetic solution. Currently, there are no standard techniques, methods, or devices that exist for the simple, large scale isolation and refinement of liposuction-harvested adipose tissue. Although a number of specialized canulas, needles and methods for tissue harvest and preparation exist, these techniques are tedious and inefficient. Often, the harvested fat is introduced into a centrifuge further traumatizing the fat and adding more steps to the process before the adipose tissue is re-injected back into the patient. As a result, centrifuge-free processes have been developed.
One example of a centrifuge-less system may be found in U.S. Patent Application Publication No. US2006/0093527 to Buss. In general terms, the Buss harvesting and irrigation device is in the form of a syringe housing open on both ends and constructed to receive a removable filter chamber that slides within the housing. One end of the housing may be coupled to a conventional harvesting canula. The housing may form an airtight chamber for holding a vacuum pressure. The tubular filter chamber includes a porous surface and is supported within the housing and spaced apart from the interior wall of the housing so that fluid may flow freely through the filter chamber and along a space between the outer filter chamber and the inner surface of the housing. The filter is sized to contain a majority of fat cells aspirated into the filter from a lumen in the chamber. Fluids for washing the harvested fat cells may be aspirated through the harvested material and out through the porous material while holding the fat tissues within the filter chamber. While this device does provide some advantages over prior solutions and may be suitable in some situations, there are a significant number of components that must manufactured and assembled to construct the device as well as a considerable amount of personal manipulation of the syringe plunger needed to perform the procedure. This includes several plunger retractions and depressions in order to fully pack fat into the syringe housing and also to draw in irrigation fluids to complete the process. This adds to the complexity of the overall training process as well.
Another example may be found in U.S. Patent Application Publication No. US2007/0225686 to Shippert. In general terms, the Shippert tissue transplantation apparatus includes a collection vessel interconnected to a harvesting canula. The vessel defines a chamber in which a series of tissue collecting syringe bodies are coupled to a manifold also in connection with the harvesting canula to provide multiple filling stations. Each syringe body is perforated to retain fatty tissue in the syringe body while allowing other smaller tissues to exit the syringe body. The chamber is also connected to a vacuum source to draw tissue from the canula into the manifold and on into one or more of the syringe bodies. Under the same vacuum, some of the extraneous tissue is drawn out of the syringe bodies leaving fatty tissue behind.
Once the desired quantity of fatty tissue is collected, a syringe body may be disconnected from the manifold mount. However, an additional sleeve is required to slip over the outer surface of the syringe body to form a sleeve or protective shell and seal before the syringe may be used. Otherwise, the fatty tissue would simply extrude out of the perforated syringe body as the plunger was depressed.
In another variation of the Shippert system, the harvested tissue is first directed into a tissue washing reservoir containing a fluid bath. However, the entry and exit ports are both provided on the lid of the reservoir and, as explained in Shippert, the washing reservoir must be tipped over onto to its side so as to cover the exit port with washed tissue to allow the washed tissue to be suctioned from the tissue washing reservoir into a manifold in communication with the perforated syringe bodies.
Yet another variation described in the Shippert publication reveals the use of a collapsible filter bag within a collapsible collection bag held within the collection canister to receive fatty tissue from the harvesting device. The filter may be used to separate out fatty tissue into the interior of the collection bag from other fluids under suction also introduced into the collection bag. However, in order to access the fatty tissue in the filter bag, the bag must be removed from the canister and the collection bag manipulated to decant unwanted fluids. If washing the tissue is desired, the collection bag is re-introduced into the canister and a fluid additive is added while the bag is massaged by hand to mix and rinse the fatty tissue. Transferring the collected fatty tissue into a syringe involves forcing tissue through an upper port in the collection bag into a syringe body. While providing a useful multi-stage filling station, the number of steps using these Shippert devices results in a cumbersome harvesting and re-injection process that may be improved upon.
While primarily used for tissue specimen collection, another solution for separating tissue may be found in U.S. Pat. No. 5,624,418 to Shepard. In Shepard, a collection and separation device is disclosed that includes a fluid collection container having a lid with a fluid/tissue inlet port and a fluid outlet port that may be coupled to a suction source and a tissue harvesting device. The container also includes a pair of ribs with a lower positioning ledge upon which a pair of tissue collection baskets or traps are positioned above the bottom of the container. While the bottom surface of the container is solid throughout, each basket includes a plurality of fluid flow apertures through which body fluids may pass through while retaining larger tissue specimens in the basket. Fluid collected below the baskets is suctioned up through the fluid outlet port to drain the container, except for the tissue specimens remaining in the baskets. The lid may also be rotated to aligned each basket with the entry port. However, there is no means to access the collected tissue specimens with first removing the lid resulting in an increased exposure to the surrounding air. The baskets may also be removed for further tissue analysis.
Despite these solutions to date, the need remains for an efficient, simple to use, low cost manufacture and assembly tissue collection and processing device that reduces the trauma to harvested tissue, improves the amount of useful tissue, and maintains a sterile processing environment.